Publish Process Model as Web Service

Hi,
I have published a Process Model as Web Service, having one optional Parameter, also created one more Process Model where i have used Call Web Service Smart Service to invoke my above Created Service ...?WSDL file along with pv! value as the parameter for the Web Service, But when start execution of my 2nd process Model, it is getting pass till the End Node (including Call Web Service Smart Service) successfully, but my Exposed Web Service Process Model is not getting Instantiate (or) Initialize, and hence i am unable to get expected response.
Please help me regarding this.

Thanks..

OriginalPostID-243869